Passimian is a black-and-white Pokémon resembling a powerfully built lemur with broad shoulders. Most of its fur is white, but it has a black muzzle, upper body, hands, feet and ankles, and tail. However, there is a wavy white ring near the tip of its tail. The fur around Passimian's head and face is longer and forms many small clumps, especially around the top of its head and under its chin. On top of its head is a pale green helmet similar to half of a coconut shell. The helmet has a small orange blaze on the front and two leaves that stand up straight attached to the back. Its eyes are partially hidden by its headwear, but its yellow sclerae and reddish-orange irises are visible. It is often seen carrying a large berry that resembles a green coconut. There are several leaves stuck on its body with saliva. The shoulders and chest all have one vertical and one horizontal leaf. While most Passimian have green leaves, the anime has shown that there is a red leaf variant on Akala Island that has one additional horizontal leaf in each area. The leaves' color and position are decided by the leader of a troop and aid in distinguishing one troop from another.
This Pokémon creates troops of 20 to 30 members. Each troop has a leader that picks 10 of the strongest members to search for food. Passimian tend to get into territorial disputes with Ambipom in their search for comfortable trees, in which they win half the time. This Pokémon's battle strategy involves throwing Berries at opponents, hard ones for damage and soft ones to obscure vision, and confusing opponents by throwing the Berry to other troop members. A troop's leader is the member that can throw these Berries the farthest. Through rigorous training, the troop improves its coordination, teamwork, and skill in handling Berries. Some Passimian are unable to handle the intensity and flee from the troop. In place of a troop leader, a captive Passimian looks to its Trainer for leadership. If its Trainer has poor form when throwing Poké Balls, it will refuse to obey.
The Melemele Greens are a group of Passimian who live in a forested area close to Iki Town. The members of that group have green markings and are from a forest behind Iki Town on Melemele Island. As such, they are referred to as (Japanese: メレメレグリーンズMelemele Greens), with their leader being nicknamed (Japanese: タイニーTiny). As the episode only aired in Asia, they don't have English names.
The Melemele Greens debuted in the banned episodeSM064. The Red Buns clan from Akala Island, led by one nicknamed Claw, had arrived on Melemele Island and asserted leadership of the Melemele Greens after taking possession of their special fruit. The Melemele Greens felt helpless under Claw's ruthless reign and simply complied. Ash decided to dress up like a Passimian, which bolstered the confidence of Tiny and the other Melemele Greens. Tiny went on to challenge Claw for the leadership of the Melemele Greens and competed alongside Ash in a Berry-tossing game on the beach. The Red Buns dominated much of the match due to their larger size, though the game encouraged the other Melemele Greens to revolt and outnumber Claw and its allies to reclaim their territory and freedom. Tiny and the other Melemele Greens eventually regained control, and later took Ash back to their nest to celebrate the victory.
The other group of Passimian that appeared in the banned episode SM064 have red markings and are from Akala Island. They are referred to (Japanese: レッドバンズRed Buns), with their leader being nicknamed (Japanese: かぎづめKagizume). They served as the antagonists of the episode.
Passimian appears to be based on a lemur, with a striking resemblance to a black-and-white ruffed lemur. Lemurs also live in large groups and are very cooperative in activities like searching for food, like Passimian. It may also draw inspiration from quarterbacks in American football.
Passimian may be a combination of pass and simian. It may also be a play on prosimian.
Nagetukesaru may be a combination of 投げつける nagetsukeru (to throw) and 猿 saru (monkey).